Originally Posted by toolman_57
Same happened to us at the end of our last trip on the re a r furnace. Luckily was still under warranty. It was the air flow sensor...when the furnace first comes on the air flow sensor checks to see if the fan is running before turning on the gas. If no air flow, the furnace turns off.
I removed the front grate under the oven and exposed the furnace. Then I took off the front panel of the furnace. Looked inside, couldn't see anything dusty clogged or out of the ordinary wiggled the 2 wires on the furnace, they feel secure. Then tried it again and it works.
Not sure what caused it to not work, but it is working again.